1 88 Bulletin American Museum of Natural History. [Vol. XVI, 



preserved molar series which may be taken as the type of a 

 new species. It is probably from the upper Bridger (Fig. 13). 

 The second, third, and fourth superior premolars show well 

 developed internal cusps, thus differing widely from the 

 Wasatch and Wind River specimens. The superior molars 

 (m' -m^ = 13 mm.) are quadrate with a well developed hypo- 

 cone now almost as prominent as the protocone ; the para- and 

 metacones are conic and there is no trace of a mesostyle. 



4. Uinta (Ligurien) Stage. 



The genus in this stage is represented by three specimens : 

 two parts of jaws, Nos. 2078, 2078a, also the molar series 

 No. 2079, which unmistakably belongs to Hyopsodus , but 

 indicates a new species. 



Fig. 15. Hyopsodus uin- 

 tensis. Am. Mus. No. 2078a. 

 Twice natural size. 



Fig. 16. Sarcoleinur fitrcntiis. Type. Am. Mus. Cope, 

 No. 5008. A^ superior, A^ ^ internal, /I '^, external views of 

 teeth and jaw. Twice natural size. 



(Sp. 57) Hyopsodus uintensis, sp. nov. 



Type No. 2079, Am. Mus. A right maxilla containing p*-m*. 

 Superior molars with broad, well defined external cingulum, but no 

 mesostyle; m'-m=' = 12.5 mm. Hypocone feeble or wanting on m". 

 The level is Horizon C or the upper true Uinta beds of Utah. 



